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  • Working on R600A unit.

     fixbear updated 1 month ago 3 Members · 3 Posts
  • olivero

    March 17, 2021 at 2:35 pm

    Hello Everyone,

    Wanted to share some insight as I had the opportunity to work on an R600A unit the other day.

    Someone stabbed the evaporator plate trying to de-ice it and punctured it, letting the 1 oz of R600A out and then calling me to see if I could fix it over the $400 replacement.

    I got a hold of the unit and checked the plate, maybe an 1/8″ hole and thought I can braze that, so I sanded it off and it was aluminum. So I torched it and used a special rod I got from a co-worker to fix aluminum holes and it worked out great.

    I then pressure tested it at 200 PSI and found out that the evaporator plate doesen’t like 200 PSI and it got all bent out of shape XD

    So I fixed the plate, let it sit and all was well, then I pulled a vac, got a can of R600A and their “Special” adapter tool and tried to weight it in with my normal refrigerant scale, didn’t work too well so I just put some in there, started it and slowly added until the SH got up to where I wanted it and it was cooling great.

    Really a painless experience despite not having the right tools for it, I’m sure with the kits coming out now, it’s probably even better BUT it was surprisingly easy.

    Some recommend removing the access point but I don’t really get the point of that, I’ve seen more leaks because of pinholes, cracked joints, bad braze joints or cracks due to the pipes rubbing than I have failed schraders.

    so I left mine on there, leak checked it and put a cap with a seal on it, so that should do it.

    I will say that one thing I could’ve done better was instead of unbrazing the suction stub, I should’ve cut it, I assumed all the R600A was out when I did it, but there was no way to tell for sure, in the future I’ll cut it and then hit it with nitro to make sure it’s all gone before I light up.

    Just wanted to share the experience since it seems not everyone has had a chance to work on one yet.

  • Denny

    May 7, 2021 at 5:41 am

    Great info, Olivero.

    My 290 and 600 experience is growing as MCD switches to propane refrigerants. I serviced one in the store a while back and also ran into the scale sensitivity issue. Yellow Jacket makes a REALLY nice all in one kit (with a price that matches!!!) that has the charge hoses, scale, adapter fittings, crimp pliers, etc. Everything but the can and a torch. Highly recommend you guys get one.

    In the meantime, if you’re saving the change you find in the parking lot on the way in to the store, I was told by the gurus at Emerson that I was to use my ears for charge. They suggested metering it in S-L-O-W-L-Y, and when it gets to it’s happy place, you’ll hear the difference in the compressor (only if you don’t have the carbon based setup). SOB, if they weren’t right. It hit it’s “stride”, and a double check of the SH showed it close enough to not mess with it any longer.

    Since then I haven’t used that method, but I too leave the schrader fittings on. Doublecheck your schrader seals are compatible with the refrigerant, though. It’s not the pressure, 410a systems operate just as high if not higher, and I have yet to see an HVAC unit with the service fittings deleted. Just sayin’… The rub seems to be with leak possibility. 404 or 410a doesn’t create a news story if it leaks and finds a combustion source….

  • fixbear

    May 10, 2021 at 5:33 pm

    I then pressure tested it at 200 PSI and found out that the evaporator plate doesen’t like 200 PSI and it got all bent out of shape XD

    Most of the machines I’ve seen with plate evaporators are only rated at 150psi on the low side. They are definitely designed to be throw always like the cheap kegerators.

    Be very careful of that Bituminus braze material. It melts at 150F and has been used in fire sprinklers as the fusable link for decades. Not for the high side at all.

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